31 August 2017
We told you so.
A lot is being written about the fact that the urban sprawl and poor flood control planning greatly exacerbated the catastrophe in Houston, but there have indeed been warnings from scientists for years that we must prepare for more extreme rain events and higher sea levels. The science behind these increased rainfall episodes is solid, and it all goes back to an equation every meteorologist learns. It’s called the Clausius-Clapeyron equation. I’ll spare you the math (go here) but the gist of it is pretty easy to get. Raise the temperature one degree C and the atmosphere can hold 7% more water vapor.
A group of scientists, including climate expert Michael Mann and Hurricane expert Kerry Emanuel, wrote a paper two years ago that indicates that because of this relationship and rising sea level, a 100-year flood is becoming a 25-year flood. The paper was about New York City but it applies generally everywhere; higher sea level and warmer air mean flooding rains that break records will happen much more frequently. Below is a quote from the abstract:
We find that mean flood heights increased by ∼1.24 m (due mainly to sea level rise) from ∼A.D. 850 to the anthropogenic era, a result that is significant at the 99% confidence level. Additionally, changes in tropical cyclone characteristics have led to increases in the extremes of the types of storms that create the largest storm surges for New York City. As a result, flood risk has greatly increased for the region; for example, the 500-y return period for a ∼2.25-m flood height during the pre-anthropogenic era has decreased to ∼24.4 y in the anthropogenic era. Our results indicate the impacts of climate change on coastal inundation and call for advanced risk management strategies.
Asking if climate change caused Harvey is like asking which direction is north at the South pole. Fingerprint studies will likely be done that can answer some specific questions, but when the ocean and the air are warmer, then there’s no doubt that climate played a role. Clausius-Clapeyron said so 150 years ago.
The question that needs to be asked here was if Texas employed any advanced risk management strategies. This is certainly not a popular question to ask right now when so many have had their lives turned upside down by this catastrophe, but It’s a fair question. The answer seems to be no, but before you blame the politicians of Texas for doing nothing, you should ask yourself this question: If the top state officials had campaigned on a platform advocating for planning for rising sea levels (and greater rain events due to climate change), would they have had a chance at being elected?
I think we both know the answer to that.
Maybe the real blame is giving out high school diplomas without teaching the scientific method, cognitive bias, and critical thinking skills to future voters. When people no longer have the skills to discern fact from myth, these things happen.